The present invention relates to stick type hand brake lever means for vehicles, and more particularly to safety means for such stick type hand brake lever means.
Conventionally, a stick type hand brake lever assembly includes a plunger mounted on an elongated guide for axial slidable movements and for rotation about its own axis. A brake actuating wire is attached directly or through a link to one end of the plunger and an operating handle is provided at the other end so that the hand brake is applied by gripping the operating handle and pulling axially the plunger along the guide. In order to have the plunger held at the pulled-out position, the plunger is provided with a locking mechanism which can be released by rotating the plunger about its axis. Usually, such locking mechanism is comprised of ratchet teeth formed on the plunger and a retaining pawl provided on the guide or any other stationary member.
In this type of hand brake lever assembly, problems have been experienced in that in the brake-applied position the handle may be rotated by being inadvertently touched by the driver or anyone else causing the plunger to rotate. This rotation of the plunger releases the plunger locking mechanism to thereby have the plunger returned to its retracted position simultaneously releasing the hand brake.
Hithertofore, various proposals have been made for avoiding such problems. For example, there has been proposed to make the operating handle freely rotatable in the pulled-out position when someone inadvertently touches the handle, so that the rotation of the handle does not cause any rotation of the plunger. In this solution, however, it is required that the operating handle be rotatable without any limitation in the rotating angle but it must be held against free rotation under its own weight or under an inertia force. Further, means must be provided for making it possible to release the plunger locking mechanism by putting the handle at a certain relationship with the plunger. However, none of prior proposals have been satisfactory in meeting the above requirements.